docs: def configure_rmq_ssl_on(self, sentry_units, deployment,
                               port=None, max_wait=60):
          """Turn ssl charm config option on, with optional non-default
          ssl port specification.  Confirm that it is enabled on every
          unit.
  
          :param sentry_units: list of sentry units
          :param deployment: amulet deployment object pointer
          :param port: amqp port, use defaults if None
          :param max_wait: maximum time to wait in seconds to confirm
          :returns: None if successful.  Raise on error.
          """
          self.log.debug('Setting ssl charm config option:  on')
  
          # Enable RMQ SSL
          config = {'ssl': 'on'}
          if port:
              config['ssl_port'] = port
  
          deployment.d.configure('rabbitmq-server', config)
  
          # Wait for unit status
          self.rmq_wait_for_cluster(deployment)
  
          # Confirm
          tries = 0
          ret = self.validate_rmq_ssl_enabled_units(sentry_units, port=port)
          while ret and tries < (max_wait / 4):
              time.sleep(4)
              self.log.debug('Attempt {}: {}'.format(tries, ret))
              ret = self.validate_rmq_ssl_enabled_units(sentry_units, port=port)
              tries += 1
  
          if ret:
              amulet.raise_status(amulet.FAIL, ret)